8-Hydroxyquinoline based chitosan derived carbohydrate polymer as biodegradable and sustainable acid corrosion inhibitor for mild steel: Experimental and computational analyses.

The present study reports the synthesis, characterization and corrosion inhibition effects of chitosan (CH) and its 5-chloromethyl-8-hydroxyquinoline derivative (CH-HQ) for mild steel in acidic medium. The synthesized CH-HQ was characterized using 1H NMR and FT-IR spectroscopic methods. Corrosion inhibition efficiencies of CH and CH-HQ were measured using electrochemical and chemical techniques. The surface protection ability of the inhibitor molecules was also ascertained by surface analysis, while computational study was used to further justify the adsorption tendencies of the molecules on mild steel surface. CH-HQwasobserved to exhibit better protection efficiency than CH, as the highest inhibition efficiencies were recorded to be 78% and 93% for CH and CH-HQ, respectively. Potentiodynamic polarization studies revealed that CH and CH-HQ are mixed-type corrosion inhibitors over the studied temperature range (298 K ± 1 to 328 K ± 1). SEM-EDS studies were performed to demonstrate the adsorption of CH and CH-HQ on the mild steel surface. Adsorption behavior of the CH and CH-HQ was also supported by UV-visible (UV-vis) spectrophotometric analyses. Monte Carlo simulations (MC) and density functional theory (DFT) calculations were carried out to corroborate the experimental results.

Synthesis, DTA, IR and Raman spectra of penthylenediammonium hexachlorostannate NH3(CH2)5NH3SnCl6.

The Raman and IR spectra of NH3(CH2)5NH3SnCl6 have been measured at ambient temperature. It is shown that the cations in the compound assume a symmetry lower than C2v. Combination bands observed in the 2100-1800 cm(-1) region in the IR spectrum of NH3(CH2)5NH3SnCl6 indicate that the compound contains the C-NH3 grouping, the bands are discussed and their assignment are suggested. No evidence of existence of hydrogen bonding is found from the infrared spectrum in the region of 2800-3200 cm(-1); anions and cations are found not connected by hydrogen bonding and are therfore isolated. The Raman spectrum of anions can be interpreted in terms of disordered groups, not clearly showing the predicted splitting of bands.